Precision divider gage



June 9, 1964 N. sAMA 3,136,068

PRECISION DIVIDER GAGE Filed April 19, 1962 United States Patent() "ce 3,136,06 PRECHSHGN DiViDER GAGE Nicholas Sanna, Cora Gables, Fla. (5991 Sil. 76th St., Miami, Fia.) Filed Apr. 19, 1962, Ser. No. 188,729 8 Claims. (Ci. 113-162) This invention relates to a device for obtaining a fixed fraction of some given dimension.

It is an object of Vthis invention to provide a divider gage whereby the midpoint, or some other such ratio, of a given dimension can be accurately found.

It is a further object of this invention to provide a divider gage whereby a given fraction of a given dimension can be automatically found without requiring recourse to numerical methods. y

It is a further object of this invention to provide a divider gage which by careful manufacture can quickly locate a given fraction of a dimension to an accuracy of 0.001 or better.

Further objects and advantages of the invention will be apparent from the following description, taken iny conjunction With the drawings, wherein:

FIGURE 1 is a view in perspective of the invention;

FIGURE 2 is a front elevational view;

FIGURE 3 is a side elevational view;

FIGURE 4 is a section taken along the lines 4 4 of FIG. 2 .and looking in the direction of the arrows, with the scribers 19 and 2li of FIGURE 1 not being shown for clarity; and

FIGURE 5 is a section taken along the lines S-S of FIG. 2 and looking in the direction of the arrows with the scriber 20 of FIGURE 1 not being shown for clarity.

Referring now to the drawings, the slide 1, having V-runners 2 and 3:, is adapted to travel along on Vf grooves 4 and 5. The J-grooves 4 and 5 are cut parallel to each other and at some angle 6 to the edge BC of the frame or block 7. The angle 6 is determined by the desired division ratio which the divider gage may be required to provide. For purposes of illustration, and also since it is the most useful case, we shall take the angle 6 such that tangent 6)=0.5. For this case, the divider gage can be used to nd the midpoint of any arbitrary dimension within the range of the instrument.

The slide 1 is kept in proper position by holding means comprising the bolt 8 and thumbscrews 9 and 11i. The bolt 8 is made with a rectangular shoulder Z9 which rides in the groove 27 in block 7. The rectangular washer 24 tits over the bolt 8 and rides in the groove 28 of block 7, the door of the groove defining a rear reference face. Thusby tightening thumbscrew 11i, the bolt 3 can be kept fixed at any desired position along the slot 30.

Provision is made for tine adjustment of the position of slide 1 by means of the screw v13', which is threaded into the bolt 8 at 14. A circular shoulder 15 on the screw 13 rests against a shoulder in a circular hole in slide 1, as shown in section in FIG. 5. The other side of the shoulder on screw 13 rests against one face of the circular collar 16. The collar 16 is so made that the screw 13 will turn freely in it. A set screw 1d holds the collar 16 Vand thence the screw 13 in position. The knurled knob 17 is press-fitted onto screw 13 after insertion of the collar 16. The circular guide hole 2.5 shown in FIG. 5 is of the same diameter as the screw 13 so that screw 13 will turn freely in it.

The operation of the fine adjustment means is as follows: with thumbscrew tight, loosen thumbscrew 9 slightly. Then turning the screw 13 by means of knob 17 will allow slide 1 to move relative to the bolt ti. The range of ne adjustment is determined by the length of the slot 26, in which the bolt 8 rides.

ananas Patented .lune 9, 1964 For accurate and smooth operation of the tine adjustment mechanism, there should be a dat steel or Ybronze spring washer between washer 23 and thumbscrew 9. This will keep the slide snug against the V-grooves when thumbscrew 9 is slightly loosened.

The scribers 19 and Ztl are to be made of tool steel, hardened and tempered. They are mounted to faces 11 and 12 of slide 1 by means of screws 21 and 22.

An important aspect of this vinvention is the following manufacturing detail: by clamping the slide 1 at the extreme upper left position in FIG.. 2, .and machining face 11 of slide 1 together with face ABCD of block 7, and face 12 of slide 1 together with face ABEF of block 7, accurate alignment and parallelism of said pairsof faces are ensured. Hence the line of intersection of facesl-11 and 12 of slide 1 will always intersect at right angles an imaginary line which passes through the point B of block 7 and is parallel to the VK-grooves 4 and 5. It is therefore a geometrical consequence that the distance between face 11 on the slide 1 and face ABCD of block 7 wiil alwaysbe one-half the distance between face 12 on slide 1 and face ABEF of block '7, no matter where the slide is located along the slot 30.

Further objects and advantages of thisinventionwill become apparent from a description of its use. Suppose it be required to find the center of an end face of an accurately machined cylindrical shaft. Then the following will quickly locate this center: l

(1) Place the shaft on a machinists surface plate, or any other such flat surface, such that the axis of the cylinder is parallel to the surface plate.

(2) Set a machinistsv dial indicatorto the height of the top of the shaft. K

(3) Place the divider gage on the surface plate such that'it rests on face ABEF.

(4) Loosen slightly thumbscrewsy 9 and 1t) and move the slide V1 such that face 12 of slide'1 is at approximately the same height as the dial indicator. Tighten thumbscrew 10i.

(5) Using the `tine adjustment screw 13, set the face 12 of slide 1 to the dial indicator height. This is easily done by using the face of scriber 19 which is in contact with face 12 of slide 1. Tighten thumbscrew 9.

' (6) Turn the divider gage over so that face ABCD rests on the surface plate.

(7) Scribe in two diameters of the shaft using the scriber 20. The intersection of the two diameters locates the center.

A similar procedure can be used for objects having different shapes.

A few comments are in order:

(1.) The thickness AB of the block should be sutiicient to give stability.

(2) While the relative sizes ofthe lengths BC and BE are not important, the range of the instrument is increased if BE=1/2BC, for then an imaginary line throughA the point B and parallel to the V-grooves 4 and 5 will also pass through the point G. Hence the instrument can be used utilizing the faces opposite faces ABCD and ABEF, in which case the maximum length which can be divided will be equal to BC.

(3) By making scriber 19 twice as thick Vas scriber 20, and reversing the scribers so that the scribing edges are away from faces 11 and 12 of slide 1, the instrument can handle dimensions down to zero.

(4) By proper use, the instrument can be used as a distance multiplier.

A divider gage such as this would be very useful in 0 everyday machine Shop practice. It can be manufactured as a planer gage, a machinist contemplating buying a said planer gage can, for slight eXtra cost, obtain instead an instrument which can fulll the additional functions described in the foregoing.`

It will be apparent to those skilled in the art that Various changes may be made in the above invention, Without departing from the spirit thereof, and therefore the invention is not limited by that which is shown in the drawings and described in the specification, but only as indicated in the appended claims.

What is claimed is:

1. A divider gage comprising; a frame having top, bottom and side surfaces with the opposing side surfaces and the opposing top and bottom surfaces being parallel to each other and with the adjacent surfaces being perpendicular to one another, a front face and a rear reference face in a plane perpendicular to the said surfaces, said front face having a pair of parallel grooves with one of the said grooves on each side of a diagonal of the front face and parallel thereto, said grooves being continuous substantially across the front face; a slide adapted to be slidably traveled over the front face parallel to said diagonal path in a plane parallel to the rear reference plane such that any point on the slide is constrained to travel in a straight line parallel to the rear reference plane; guide means carried on the slide engaging the parallel grooves; releasable holding means carried by the slide to maintain the slide in a fixed position relative to the frame; and scribing means rigidly attached to the slide and having a scribing point such that, (a) the shortest distance between the point of the scribing means from the plane of the bottom surface of the frame and (b) the shortest distance between the point of the scribing means from the plane of the side surface of the frame, which together with the bottom surface define the point through which the diagonal passes, are in the same ratio as the slope of the diagonal.

2. A divider gage comprising; a frame having top, bottom and side surfaces with the opposing side surfaces and the opposing top and bottom surfaces being parallel to each other and with the adjacent surfaces being perpendicular to one another, a front face and a rear reference face in a plane perpendicular to the said surfaces, said front face having a pair of parallel grooves with one of the said grooves on each side of a diagonal of the front face and parallel thereto, said grooves being continuous substantially across the front face; a slide adapted to be slidably traveled over the front face parallel to said diagonal path in a plane parallel to the rear reference plane such that any point on the slide is constrained to travel in a straight line parallel to the rear reference plane; guide means carried on the slide engaging the parallel grooves; releasable holding means carried by the slide to maintain the slide in a Xed position relative to the frame; and a first and a second scriber rigidly attached to the slide and each having a scribing point such that (a) the shortest distance between the scribing point of the rst scriber from the plane of the bottom surface of the frame and (b) the shortest distance between the point of the second scriber from the plane of the side surface of the frame which together with the bottom surface define the point through which the diagonal passes, are in the same ratio as the slope of the diagonal.

3. A divider gage comprising; a frame having top, bottom and side surfaces With the opposing side surfaces and the opposing top and bottom surfaces being parallel to each other and with the adjacent surfaces being perpendicular to one another, a front face and a rear reference face in a plane perpendicular tothe said surfaces,

said front face having a pair of parallel grooves with one of the said grooves on each side of a diagonal of the front face and parallel thereto, said grooves being continuous substantially across the front face; a slide adapted to be slidably traveled over the front face parallel to said diagonal path in a plane parallel to the rear reference plane such that any point on the slide is constrained to travel in a straight line parallel to the rear reference plane; guide means carried on the slide engaging the parallel grooves; releasable holding means carried by the slide to maintain the slide in a fixed position relative to the frame; and a first and a second scriber rigidly attached to the slide, said first and said second scriber each having a respective straight scriber edge such that (a) the shortest distance along a line perpendicular to the straight scribing edge of the rst scriber to the plane of the bottom surface of the frame and (b) the shortest distance along a line perpendicular to the straight scribing edge of the second scriber to the plane of the side surface of the frame which together with the bottom surface define the point through which the diagonal passes, are in the same ratio as the slope of the diagonal.

4. A divider gage as set forth in claim 1 wherein adjustment means to move the slide relative to the holding means are supported on the slide.

5. A divider gage as set forth in claim 2 wherein adjustment means to move the slide relative to the holding means are supported on the slide.

6. A divider gage as set forth in claim 3 wherein adjustment means to move the slide relative to the holding means are supported on the slide.

7. A divider gage comprising, in combination; a frame having top, bottom and side surfaces with the opposing top and bottom surfaces being parallel to each other and with the adjacent surfaces being perpendicular to one another, a front face and a rear reference face in a plane perpendicular to said surfaces; a slide movable with respect to the frame; mutually inter-engaging guide means on said slide and said frame to guide movement of said slide relative to said frame over the front face thereof along a diagonal path parallel to a diagonal of the front face of said frame such that on movement of the slide any part thereof is constrained to travel in a straight line parallel to the plane of the rear reference face; mutually inter-engaging holding means carried with the slide and movable therewith and connected for movable engagement with the frame to engage the frame and releasably hold the slide in the fixed position relative to the frame; and a first and a second scriber rigidly attached to the slide, said first and said second scriber each having a respective straight scriber edge such that (a) the shortest distance along a line perpendicular to the straight scribing edge of the first scriber to the plane of the bottom surface of the frame and (b) the shortest distance along a line perpendicular to the straight scribing edge of the second scriber to the plane of the side surface of the frame which together with the bottom surface define the point through which the said diagonal passes, are in the same ratio as the slope of the diagonal.

8. A divider gage as set forth in claim 7 wherein adjustment means to move the slide relative to the holding means are supported on the slide.

References Cited in the file of this patent UNTTED STATES PATENTS 1,040,774 Schamel Oct. 8, 1912 2,242,116 Donoway May 13, 1941 2,518,080 Schury Aug. 8, 1950 2,876,552 Zelnick Mar. 10, 1959 

1. A DIVIDER GAGE COMPRISING; A FRAME HAVING TOP, BOTTOM AND SIDE SURFACES WITH THE OPPOSING SIDE SURFACES AND THE OPPOSING TOP AND BOTTOM SURFACES BEING PARALLEL TO EACH OTHER AND WITH THE ADJACENT SURFACES BEING PERPENDICULAR TO ONE ANOTHER, A FRONT FACE AND A REAR REFERENCE FACE IN A PLANE PERPENDICULAR TO THE SAID SURFACES, SAID FRONT FACE HAVING A PAIR OF PARALLEL GROOVES WITH ONE OF THE SAID GROOVES ON EACH SIDE OF A DIAGONAL OF THE FRONT FACE AND PARALLEL THERETO, SAID GROOVES BEING CONTINUOUS SUBSTANTIALLY ACROSS THE FRONT FACE; A SLIDE ADAPTED TO BE SLIDABLY TRAVELED OVER THE FRONT FACE PARALLEL TO SAID DIAGONAL PATH IN A PLANE PARALLEL TO THE REAR REFERENCE PLANE SUCH THAT ANY POINT ON THE SLIDE IS CONSTRAINED TO TRAVEL IN A STRAIGHT LINE PARALLEL TO THE REAR REFERENCE PLANE; GUIDE MEANS CARRIED ON THE SLIDE ENGAGING THE PARALLEL GROOVES; RELEASABLE HOLDING MEANS CARRIED BY THE SLIDE TO MAINTAIN THE SLIDE IN A FIXED POSITION RELATIVE TO 